Air circulating unit



Jan. 25, 1955 B. H. MILLER AIR CIRCULATING UNIT Filed April '16, 1951 dv e m m n T r N u ,m m 1 m m E f C W W 5 y Y 2 B I 7 R A W k 1 r 4 w a,1

United States Patent AIR CIRCULATING UNIT Bryce H. Miller, Los Angeles,Calif.

Application April 16, 1951, Serial No. 221,173

4 Claims. c1. 98116) This invention relates to ventilators forexhausting the air from under the roof of a building or forrecirculating the air within the building.

The main objects of this invention are: to provide a ventilator in theform of a tubular stack adapted to be installed through the roof of abuilding, usually of the industrial type, and being constructed andarranged so that by rotating the circulating fan in one direction, warmair banked under the roof of the building is blown downwardly andre-circulated and, when the circulating fan is operated in the oppositedirection, the air will be exhausted from under the roof of the buildingand discharged into the atmosphere above the roof.

A further object of this invention is to provide an improvedconstruction in which the amount of air intake, when used as are-circulator, may be varied or adjusted according to the conditionspresent for the amount of recirculation desired under the circumstancespresent.

An illustrative embodiment of this invention is shown in theaccompanying drawings, in which:

Fig. 1 is a vertical, medial, sectional view taken through theventilating apparatus and shown installed on the roof of a building, theroof being shown in broken lines.

Fig. 2 is a top plan view of the same.

In the construction shown in the drawings, a main duct or stack oftubular construction generally designated 4 is shown mounted in avertical position through the roof 6 of a building with its upper endterminating in an outwardly directed radial flange 8 in spaced relationabove the roof. The mounting on the roof is accompanied by afrusto-conical skirt or band 10 having its upper and smaller end weldedor otherwise secured to the outside of the stack 4 closely adjacent toand below the flange 8. The lower or larger end of the skirt 10 iswelded or otherwise suitably secured to the top marginal edge of acylindrical base 12. The base 12 has its lower end cut at an angle toconform to the pitch of the roof and terminates in an outwardlyextending flange 14 by which it is secured to the roof top. The base 12is of larger diameter than the stack 4 so as to be in spaced relation tothe stack and minimize heat transfer from the stack to the roof 6.

The top flange 8 is provided with a plurality of circumferentiallyspaced angle clips 16, each having one leg thereof welded or otherwisesuitably secured to the underside of the flange 8 and its other legextending upwardly and bolted to a wind band 18. The wind band 18 is oflarger diameter than the stack 4 and concentrically positioned withrespect thereto so as to provide an annular space between the band andthe outturned flange 8 of the stack. The top end of the stack is alsoprovided with a pair of diametrically positioned clips 20 to which arefreely hinged a pair of semi-circular butterfly damper valves 22 and 24which are adapted to open outwardly as shown by the broken lines 26 inFig. 1.

The lower end of the main stack 4 extends below the roof 6 into theinterior of the building and may be positioned any suitable distancebelow the roof line, depending upon the structure of the building andthe conditions present therein. The lower end of the stack 4 is flaredoutwardly and downwardly at an angle of approximately 6 to form a skirt28. A plurality of circumferentially spaced angle clips 29 are welded tothe outside of the stack close above the skirt 28.

A plurality of substantially, vertically disposed tie bolts 32, havingthreaded ends, have their upper ends passed through holes in thehorizontal legs of the angle clips 29 and anchored thereto by opposednuts 30 which embrace opposite sides of the clips. The bolts 32 extendthrough registering slotted openings provided in the skirt 28 and haverelatively long lower threaded ends adapted to pass through aperturedears 33 which are welded to the outside of a stack extension generallydesignated 34. Opposed nuts 31 are threaded on the lower ends of the tiebolts 32 for rigidly securing the extension 34 in axially adjustedposition with respect to the main stack 4. The stack extension 34 is ofcylindrical shape and of smaller size than the main stack 4 and in axialalignment therewith. The top end of the stack extension 34 is taperedinwardly as shown at 35 which cooperates with the skirt 28 to produce ajet or venturi action when the air is moved upwardly through theventilator.

Means are provided for moving air in either direction through the stackextension 34 and comprise a reversible motor 36 mounted centrally of thestack extension 34 on a plurality of bracket arms 38 forming a spiderwithin the extension. Fan blades 40 are secured to the armature shaft ofthe motor 36 and when rotated will either force the air downwardlythrough the extension or upwardly therethrough, depending upon thedirection of rotation of the motor.

The lower end of the stack extension 34 is also provided with anoutwardly extending radial flange 46 to which is secured thecomplementary flange 48 of a downwardly and outwardly flaringfrusto-conical dispersing cone 50. A plurality of bolts 51 secure theflanges together. An interior frusto-conical member 52 is also providedand mounted on radial webs 54 for distributing and dispersing the airmoved downwardly through the stack extension 34.

When it is desired to re-circulate air banked up against the undersideof the roof of a building, the motor 36 is rotated in a direction whichwill cause the fan blades 40 to blow or move air downwardly through thestack extension 34. During such operation, the valve dampers 22 and 24remain closed by gravity and air is supplied to the fan through theopening formed by the axial spacing of the extension 34 from the mainstack 4. The effective area of the intake may be varied and adjusted bymoving the nuts 31 on the threaded mounting studs 32 and this adjustmentwill, of course, vary the amount of air drawn in through the spacebetween the upper end of the stack extension 34 and the underside of thefrusto-conical skirt 28.

As the air is forced and moved downwardly through the stack extension34, a portion thereof strikes the upper surface of the distributingmember 52 and is diffused outwardly in the usual manner of airdistributors of this character.

When it is desired to exhaust the air accumulated under the roof to apoint outside the building, the motor is rotated in the oppositedirection and the circulating fan blows the air upwardly through themain stack 4 as indicated by the arrows 56. The force of the air opensthe valve dampers 22 and 24 to the position shown in broken lines 26 andthe air is exhausted to the atmosphere above the roof 6. Immediatelyupon stoppage of the fan 40, the valve dampers 22 and 24 close bygravity to the position shown in full lines in Figs. 1 and 2.

Due to the inwardly tapered portion 35 on the upper end of the stackextension 34 and the flared skirt portion 28 on the lower end of themain stack 4, the air passing upwardly through the stack will, by ventriaction, draw in a supply of air through the space between the main stackand the stack extension and due to the threaded lower ends of the tiebolts 32, the amount of this venturi action and the quantity of airdrawn therein may be adjusted and varied to suit the conditions andcircumstances.

Although but one embodiment of the invention is disclosed herein, it iscapable of taking other specific forms and it should be understood thatvarious changes can be made in the form and details without departingfrom the spirit of the invention.

I claim:

1. In a ventilator of the class described, a vertically disposedopen-ended cylindrical main stack adapted to be installed through theroof of a building with its upper end outside the building and its lowerend inside the building and having a medial roof line portion, .anopenended cylindrical stack extension, means affixed to said main stackfor dependently carrying said extenslon 1n spaced axial relation to saidmain stack and defining an air inlet opening therebetween, an upwardlyopening normally closed one-way valve damper mounted-in the upper end ofsaid main stack, and a reversible circulating fan mounted in said stackextension.

2. In a ventilator of the class described, a vertically disposedopen-ended cylindrical main stack adapted to be installed through theroof of a building with its upper end outside the building and its lowerend inside the building and having a medial roof line portion, an open-.ended cylindrical stack extension, means affixed .to said main stackfor dependently carrying said extension in spaced axial relation to saidmain stack and for varying the distance between said stack .and theextension and defining an air inlet opening therebetween, an outwardlyopening normally closed one-way valve damper mounted in the upper end.of said main stack, and a reversible circulating fan mounted in saidstack extension.

3.. In a ventilator of the class described, a vertically disposedopen-ended cylindrical main :stack adapted to be installed through theroof of a building with its upper .end outside the building and itslower end inside the building and having a medial roof line portion, anopenended cylindrical stack extension, means affixed to said main stackfor dependently carrying said extension in spaced axial relation to saidmain stack and for varying the distance between said stack and theextension and defining an air inlet opening therebetvveen, an upwardlyopening normally closed one-way valve damper mounted in the upper end ofsaid main stack, and a reversible circulating fan mounted in said stackextension, said means comprising a plurality of circumferentially spacedsupporting rods affixed to the main stack, a plurality of apertured earsaffixed to said stack extension and each receiving therethrough one ofsaid supporting rods, and a lllt threaded upon the lower end of each ofsaid r0 s.

4. A device as defined in claim 2 wherein the lower end of said mainstack is provided with ,an outwardly flaring skirt, and wherein theupper end of said stack extension is inwardly tapered and receivable insaid skirt when said stack extension is moved toward said main stack.

References Cited in the file of this patent UNITED STATES PATENTS1,575,447 Moore Mar. 2, 1926 2,089,560 'Kurth Aug. 10, 1937 2,179,893Lyon Nov. 14, 1939 2,188,741 Roberts v 1811. 30, 1940 2,439,271 ShaverApr. 6, 1948 2,541,665 Prudhon .7.. Feb. 13, 1951 FOREIGN PATENTS417,455 Great Britain .Oct. 1, 1934

